jahiaservice.java

java 写的一个新闻发布系统

// $Id: JahiaService.java,v 1.2 2002/04/04 08:13:25 pmartin Exp $
//
//                                   ____.
//                       __/\ ______|    |__/\.     _______
//            __   .____|    |       \   |    +----+       \
//    _______|  /--|    |    |    -   \  _    |    :    -   \_________
//   \\______: :---|    :    :           |    :    |         \________>
//           |__\---\_____________:______:    :____|____:_____\
//                                      /_____|
//
//                 . . . i n   j a h i a   w e   t r u s t . . .
//

package org.jahia.services;

import org.jahia.settings.JahiaPrivateSettings;
import org.jahia.exceptions.JahiaException;
import org.jahia.exceptions.JahiaInitializationException;


/**
 * This class is the root class of all the Jahia services. The
 * {@link #init init()} method is called when the service is created when the
 * Jahia server starts, and the {@link #shutdown shutdown()} is called when
 * the service has to be shutdown. Service developpers should override these two
 * methods to perform specific initialization or shutdown operations. When the
 * service needs to be restarted, a call to the
 * {@link #restart restart()} method should be done.
 *
 * @author  Khue Nguyen
 * @author  Fulco Houkes
 *
 * @version 1.2
 */
public abstract class JahiaService
{
    private String mServiceName = null;

    /**
     * This variable is true when the service has been initialized and is ready
     * to be used, method calls should fail (raise an exception) when this
     * variable is false.
     */
    protected boolean mIsServiceInitialized = false;


    //-------------------------------------------------------------------------
    /** Return true if the service is initialized and ready to be used.
     *
     * @return  Return true if the service is initialized.
     */
    public boolean isInitialized ()
    {
        return mIsServiceInitialized;
    }


    //-------------------------------------------------------------------------
    /** Check if the service is running (initialized). If it's not initialized
     *  yet, a JahiaException is thrown.
     *
     * @exception   JahiaException
     *      Throws this exception when the service is not initialized.
     */
    protected void checkService ()
        throws JahiaException
    {
        if (!mIsServiceInitialized) {
            throw new JahiaException ("Service error.",
                    "Service ["+mServiceName+"] is not initialized!",
                    JahiaException.SERVICE_ERROR, JahiaException.CRITICAL);
        }
    }


    //-------------------------------------------------------------------------
    /** Set the service name.
     *
     * @param   name
     *      String representation of the service name.
     */
    public synchronized void setServiceName (String name)
    {
        if (name != null) {
            if (name.length() > 0) {
                mServiceName = name;
            }
        }
    }


    //-------------------------------------------------------------------------
    /** Get the service name.
     *
     * @return
     *      Return a reference on the service name. Might return
     *      <code>null</code> when the service has not be named yet.
     */
    public String getServiceName ()
    {
        return mServiceName;
    }


    //-------------------------------------------------------------------------
    /**
     * Code to clean up the services ressource here. Override this method
     * with specific services shutdown codes.
     *
     * @exception   JahiaException
     *      Raise an JahiaException exception on any failure.
     */
    public synchronized void shutdown ()
        throws JahiaException
    {
        mIsServiceInitialized = false;
    }


    //-------------------------------------------------------------------------
    /** Initialize the service. Override this method if specific initialization
     *  is needed to start the service.
     *
     * @exception   JahiaInitializationException
     *      Thows this exception on any failure.
     */
    public synchronized void init (JahiaPrivateSettings jSettings)
        throws JahiaInitializationException
    {
        mIsServiceInitialized = true;
    }


    //-------------------------------------------------------------------------
    /** Restart the service by cleaning the remaining resources. This method
     *  calls the {@link #shutdown() shutdown()} and
     *  {@link #init init()} method of the service.
     *
     * @exception   JahiaInitializationException
     *      Thows this exception on any failure.
     *
     * @exception   JahiaException
     *      Raise an JahiaException exception on any shutdown failure.
     */
    public synchronized void restart (JahiaPrivateSettings jSettings)
        throws  JahiaInitializationException,
                JahiaException
    {
        shutdown ();
        init (jSettings);
    }

}